Figure 5.

(A) The plasticity of the forward connection from the left A1 to the left STG was significantly reduced after ketamine administration (P < 0.001). (B) The y-axis denotes the average value (±standard deviation) of the (scaling) parameter that encodes changes in connection strength for deviant versus standard tones. (B) Linear regression indicated a significant relation between drug effects on “control and cognition” ratings (score under ketamine minus score under placebo) and drug effects on plasticity (ratios of DCM parameters encoding condition-specific changes, that is, relative short-term plasticity under ketamine vs. placebo) in the left A1 → STG connection (F = 4.45, P < 0.006).